AET strengthens decarbonization roadmap with DNV

Global tanker owner and operator AET has been at the forefront of the industry’s decarbonization efforts for years. Headquartered in Singapore and a member of the MISC group, AET was among the first shipping companies to adopt dual-fuel LNG propulsion across multiple vessel classes (Aframaxes in 2019, DPSTs in 2020 and VLCCs in 2022). The company is also a first mover with battery hybrid systems on its lightering support vessel.

Going beyond IMO’s decarbonization ambition

While the International Maritime Organization’s first major decarbonization goal is a 20 per cent reduction in emissions by 2030 as compared to 2008 levels, AET’s own decarbonization goals go further. By 2030, AET aspires to reduce its greenhouse gas (GHG) emissions from shipping operations by 40 per cent from its 2008 baseline and achieve net-zero GHG emissions across its business and value chain by 2050.

Recognizing the technical and financial complexity of achieving these targets, AET leveraged technical insights from DNV’s Maritime Advisory team to assess and implement technologies aimed at optimizing fleet efficiency as part of its tiered decarbonization strategy.

CFD simulations reveal effects of specific optimizations

Since AET had already optimized many of its operations, the main focus of the strategy, which utilizes DNV’s Decarbonization Plan service, has been around the effects of specific technologies on emission performance and return on investment. DNV carried out computational fluid dynamics (CFD) simulations on the hull lines of each vessel class for various speed and draught conditions.

Led by Dr Karsten Hochkirch, Head of DNV’s Ship Performance Center in Hamburg, these analyses assessed the impact of design modifications on fuel efficiency and emissions. Dr Hochkirch explains: “Through CFD simulations, we can precisely assess the hydrodynamic performance of a ship, identifying the best optimization options for specific operational profiles.”

The Decarbonization Plan combines the results of these studies with operational data from DNV’s Abatement Insights database to reveal the effects of various technologies on a vessel’s emission and fuel efficiency performance.

Developing digital decarbonization dashboards

To optimize the implementation of AET’s tiered decarbonization strategy, DNV developed tailored plans covering each vessel class, allowing insights to be applied across nearly the entire fleet. This was brought to life through an intuitive digital dashboard, Satinder Virdi, DNV Project Manager, explains. “This tool gives users a comprehensive view of each ship’s technical profile, operating patterns, fuel consumption, Energy Efficiency Existing Ship Index (EEXI) ratings, and associated costs for retrofits,” he says. 

Through charts and diagrams, the dashboard illustrates projected GHG performance for the vessels relative to the IMO trajectories, with and without energy efficiency measures, as well as the return on investment when the measures are implemented. By integrating regulatory and financial considerations, AET ensures that each investment is aligned with its decarbonization roadmap.

Data and modelling give confidence in decarbonization predictions

AET uses CFD modelling to strengthen the business case for each decarbonization measure.

This approach enables a comprehensive evaluation of capital expenditure, logistics planning, and the anticipated carbon reductions and fuel savings, particularly for the first tier of its strategy.

Prioritizing decarbonization investments for tanker fleet

Being able to evaluate these options allows AET to prioritize investments, with implementation then planned around each vessel’s existing timetable. “We try to schedule these modifications for the dry dockings,” says Sobhith Hariharan, Head of Decarbonization at AET.

“This year we have close to 14 vessels docking. We’ll install propeller boss cap fins on the first four ships, pre-swirl ducts on five, and apply antifouling and ultra-low-friction coatings to seven or eight ships.”

In addition to these efforts, AET is also evaluating the potential benefits of propeller retrofits, though these are not typically applied to tankers.

Tiered decarbonization strategy

“Tier 1 consists of foundational technologies such as propeller boss cap fins, pre-swirl ducts and advanced coatings, delivering immediate efficiency improvements,” says Capt. Pallava Shukla, Director of HSSE and Decarbonization at AET Tankers.

These measures, supported by DNV's CFD studies, have the potential to reduce emissions by up to 5% per vessel.

“Tier 2 introduces innovative solutions like wind-assisted propulsion to further enhance performance, while Tier 3 focuses on transformative technologies such as fuel retrofits for long-term sustainability.” 

Applying learnings to new projects

Given the higher capital expenditure and longer lead times associated with Tier 2  projects, AET is carefully evaluating them to ensure they align with the company’s long-term sustainability and efficiency goals. 

As part of Tier 3 measures, in 2024 AET signed shipbuilding contracts for three of the world’s first ammonia dual-fuel Aframax tankers. 

In a project that further underscores AET’s commitment to decarbonizing, the company recently signed an agreement with marine battery specialist Fleetzero for the development of the world’s longest-range plug-in hybrid-electric ship. The lightering support vessel will operate primarily on battery power, reducing greenhouse gas emissions by about 82% on a tank-to-wake basis.

Fostering a culture of sustainability

AET’s decarbonization strategy is underpinned by a culture of sustainability, supported by continuous learning and performance tracking. Vessel-specific and fleet-level emissions intensity targets and KPIs ensure ongoing improvements across the fleet.

Knowledge and training are key and DNV supports AET in upskilling that will help the company better embrace new technologies.

AET also partners with the Maritime and Port Authority of Singapore and key stakeholders in the Maritime Energy Training Facility project, aiming to drive industry-wide learning.

Translating industry insights into actionable strategies

Given the evolving nature of environmental regulations and technological advancements, AET and DNV are committed to continued collaboration.

“Scientific insights and analytical tools play a key role in supporting our investment decisions and design changes,” says Capt. Pavan Kumar, Global Director, Technical – Operations, HSSE & Decarbonization at AET. “With a structured framework, we can assess progress, identify the most viable pathways, and focus on real-world solutions that drive measurable impact.”

Dr Shahrin Osman, Director of Maritime Decarbonization and the Smart Shipping Centre of Excellence at DNV, summarizes: “By leveraging our global expertise, we have been able to translate industry insights into actionable strategies for AET. We are confident that our collaboration will empower AET to continue leading the way in sustainable maritime practices.”